  export function loadJS(src) {
    return new Promise((resolve,reject)=>{
      let script = document.createElement('script')
      script.type = "text/javascript"
      script.onload = ()=>{
        resolve()
      }
      script.onerror = ()=>{
        reject()
      }
      script.src= src
      document.getElementsByTagName('body')[0].appendChild(script)
    })
  }